Magneto ignition system



Aug. 7; 1923.

C. F. KETTERING MAGNETO IGNITION SYSTEM Filed March 25. 1920 2 Sheets-Sheet 1 C. F. KETTERING MAGNETO IGNITION SYSTEM Marc ets-Sheet 2 MJYQ Q5 Patented Aug. 7 1923. v

UNITED STATES PATENT OFFICE.

CHARLES I. KETTERING, OF DAYTON, OHIO, ASSIGNOR TO DELCO-LIGHT 'COKPANY,

OF DAYTON, OHIO, A CORPORATION OF DELAWARE.

MAGNETO IGNITION SYSTEM.

Application filed Hatch 25, 1920. Serial No. 868,789.

To all. whom it may concern.

Be it known that I, CHARLES F. KEI'IER- me, a citizen of the United States of Amer ica, residing at Dayton, countyof Montgomery, and State of Ohio, have invented certain new and useful Improvements in Magneto Ignition Systems, of which the following is a full, clear, and exact description.

This invention relates to ignition systems for internal-combustionengines, and particularly to systems including a magneto having a rotatable gart mounted upon the engine fl wheel. terme a flywheel magneto.

It is an object of the invention to provide for the mounting of the rotatable magneto part upon the flywheel of an air-cooled engine wherein the flywheel is constructed to operate as a fan to cool the engine, the manner of mounting being such as not to interfere with the function of the flywheel as a fan. In this connection it is a further objectto provide a housing for the magneto in I neto'to the conductor leading to the spark taken on the flywheel end 0 order toprotect it from particles of dirt or dust, such asmight pass around the en ine during-the operation of the engine coo ing system.

As a means of carryin out the fore oing objects, the flywheel an the en 'ne' rame have cooperating provisions whic form the magneto housing.

A further ob ect is to provide a separate location for the magneto timer which shall be accessible without requiring the removal of the flywheel. I

It is a still further object of the present invention to provide a simple means for connecting the secondary winding of the mag- F urther objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawing: 1 v

Fig. 1 is an elevation partly in section I an internal-combustion engine, part of the flywheel being broken away showingthe electrical connecuch a magneto 1s generally tions between the different parts of the ignition system;

Fig. 2 is a front elevation of the timer shown in. Fig. 1, looking in the direction of the arrow 2;

Fig. 3 is a fragmentary sectional view taken on line 3-3 of Fig. 1;

Fi 4 is a view of the high tension termina shown in Fig.3, looking in the direction of the arrow 4; and I Fig. 5 is an elevational view, looking in the direction of Fig. 1, of the armature and magneto of the flywheel magneto, the magnet being shown in the position when the primary magneto circuit is interrupted to induce a sparking impulse.

' Referring to the drawings, an internal combustion engine 20 includes a base 21 supporting a crank case 22, having an outer jacket 23 to provide an air space around crank case 22 for cooling purposes. Jacket 23 supports a draft tube 24 open at the upper end at 25. Crank case 22 is provided with a removable end cover 26 carrying a crank,

shaft 36 carries a flywheel 40 which is keyed thereto by key 41. A gear 42 is provided on the crank shaft 36 which cooperates with a' gear 43 carried by the timer shaft 44.

One end of timer shaft 44 rotates within a timer casting 45 projecting outwardly from the internal-combustion engine. A plate 46 is secured to the timer casting 45 by rivets 46 and insulated from the casting by insulation strip 47. A conductor 48 is connected to plate 46 at terminal 49. A contact arm late 46 carries 50 which projects from the an adjustable contact 51 w ich cooperates with a contact 52. Contact 52 is carried by an arm 53 which is pivotally mounted on stud 54. mounted on the casting 45. A spring which is connected to the arm 53 normally tends to hold contacts 51 and 52 in contact. A block 56 provided on the arm 53 cooperates with cam shaft 44, said shaft having a flat portion 57 forming a cam cooperating with the block 56 intermittently to open contacts 51 and 52.

A non-magnetic bracket or plate 59 is secured to the end-cover 26 by screws 60. Plate 59 is provided with an aperture 61 surrounded by an annular boss 62. A coil 63 is provided with an armature core 64 having armature heads 65 and 66, said heads being secured to the plate 59 by screws 67. A primary winding 68 is wound around core 64 and insulated therefrom by insulating material 69. Secondary winding 70 is wound around the primary winding 68 and insulated therefrom by .insulatin, material 71. Insulating material 73 encircles the coil 63 and is provided with an opening .74 through which a hollow rivet 75 projects. A conically shaped non-conducting block 76 is riveted to the insulation 73 b the rivet 75 and is provided with a recess 7 A nonconducting plug 78 has an internally tapered surface which forms a seat for the block 76.

A conductor 79 having a clip 80 attached thereto is inserted within a hole in the plug 78 and is held in place by a screw 81. One end of the winding 70 projects through the hollow rivet 75 into the recess 77 and is in contact with a spring 82. Spring 82 bears against screw 81. A flanged portion 83 on the plug 78 fits within the aperture 61 of the plate 59 and is secured therein by ring 84 which is held by screws 85 against the boss 62 of the plate 59.

Conductor 79 passes through crank case 22 and jacket 23 and is connected with spark plug 35. The other end of the secondary 70 is grounded on the primary 68 having one end grounded by means of wire 94 on the plate 59. Vire 95 connects the other end of the primary 68 with a terminal 96 which is mounted on plate 59 but insulated there from. Wire 48 connects terminal 96 with the timer.

Wire 97 connects terminal 96 with condenser 98 which is grounded upon plate 59.

A non-magnetic ring 100 having a flange 101 is secured to flywheel 40 by screws 102, and caries a permanent magnet-103 provided with pole shoes 104 and 105.

The engine is started manually by rotating by means of a handle 110 the flywheel 40 in the direction of arrow 120. Some time during the compression stroke of the engine the per'manent magnet 103 will be in a posilion such that the armature head 65 will just bridge the gap between poles 104 and 105, short circuiting the flux of themagnet 103 from the armature core 64. Just prior to the proper firing time, the pole 105 will be leavlng the head 65 and overlapping head 66, and the pole 104 will be overlapping the head 65. At this time there is a sudden inrush of flux from the magnet 103 across the armature core 64 causing the building up of current in the primary coil 68. By the time the magnet 103 is in the position shown in Fig. 5, the coil 68 will have built; up to the maximum. This is the pro er instant for firing, and the flat portion 5 on shaft 44 is arranged at this instant to cooperate with arm 53 to separate contacts 51 and 52 to interrupt the primary circuit. The direction 'of rotation of cam shaft 44 is indicated by arrow 121.

The interruption of the primary circuit will cause a sparking impulse to be induced in the secondar winding 70 thereby causing a spark to jump at the snark plug 35.

This particular construction and operation of the magneto generating elements is not of itself my invention but is described and claimed in the patent to R. A. Oglesby No. 1,279,750, issued September 24. 1918.

During each engine cycle there will be two revolutions of the flywheel hence there will be two abrupt reductions of magnetic flux in the armature core 64 during each engine cycle. By providing that thecam shaft 44 operates at one half engine speed there will be but one interruption of the primary circuit during each engine cycle to provide for the induction of a sparking impulse in the secondary. For a two cycle internal-combustion engine the cam shaft 44 may beoperated at engine speed.

The periphery of the flywheel 40 is provided with spaced blades 40 which during the operation of the engine create a draft causing the circulation of air about the cylinder 28 and between the crank case 22 and the jacket 23 and out through the flywheel, this current being indicated by the arrows 122 in Figs. 1 and 3. Referring to Fig. 3 it will be noted that the plate 59 and the ring 100 cooperate together to form an enclosure or housing forthe magneto ele ments in such'a manner as not to interfere with the function of the flywheel 40 as a fan. Ring 100 serves to direct air currents to the fan blades 40. This housing protects the magneto elements from particles of dirt and moisture which may be drawn through the flywheel during the cooling of the engine. The ring 100 also protects the magneto elements' from anything which may happen to he dropped down through the spaces between the flywheel fan blades 40 when the engine is stationarv.

Instead of locating the magneto timer within the housing for the magneto generating elements, the timer is located outside of the flywheel and in a position which is readily accessible for pur see of adjustment or making repairs. 'l his location of the timer is much more advantageous than gether with the ring 100 supporting the permanent magnet 103 forms one unit, which is easily assembled upon the crank shaft 36, and the plate 59 or support carrying the magneto'armature and windings and the terminals leading to the timer and spark plug forms another unit which may be easily attached to the crank case cover 26.

While the form of mechanism herein shown and described constitutes a preferred embodiment of one form of the invention,

it is to be understood that other forms might be adopted and various changes and alterations made in the shape, size and proportion of the elements therein without departing from the spirit and scope of the invention.

What I claim is as follows:

1. In a device of the kind described, the

combination with an engine comprising a flywheel cooling fan; of means carried by the engine frame and flywheel fan adapted to cooperate to form a housing within the flywheel fan; and a magneto-generator having stator and rotor elements carried. within said housing by the engine frame and flywheel fan respectively.

2. In a device of the kind described, the combination with an internal combustion engine comprising a fl wheel fan; of a magneto-generator inclu ing a stator and a rotor; a housing mounted on the flywheel and adjacent the engine frame, said rotor being carried by the flywheel within the housing and a support for the stator mounted on the engine frame adjacentthe flywheel, said housing and support cooperating together to provide an enclosure for the magneto generator while permitting the passage of air through the fan.

3. n a magneto ignition system, the combination with an internal combustion engine having air cooling provisions including a jacket providing an air passage opening out adjacent one end of the engine frame, anda flywheel provided with peripherally arranged blades and located adjacent said jacket opening; of a magneto generator ineluding a' stationary armature and a movable magnet; a circular plate supported by the engine frame adjacent said jacket opening and providing an annular air passage communicating with the fan blades, said plate supporting the magneto armature; and a ring mounted upon the flywheel for supporting the magnet and extending adjacent to the plate to cooperate therewith to provide a magneto housing, said ring serving also to direct air currents to the fan blades.

4. In a magneto ignition system, the combination with an internal combustion engine having air cooling provisions including a jacket providing an air passage having a circular opening adjacent one end of the engine frame, and a flywheel provided with peripherally arranged blades and located closely adjacent to said circular jacket opening; of a magneto-generator including a stationary armature and a movable magnet; means for supporting the magnet by the flywheel; an armaturesupport carried by the engine frame adjacent said jacket opening; and a high tension conductor connected with the armature and detachably secured to said armature support and extending within said .jacket opening and thence out through said jacket.

5. n a magneto-ignition system, the combination with an internal combustion engine having a cup-shaped flywheel fan located ad jacent one end of the engine frame; of a magmete-generator including a stationary armature and a movable magnet; means for supporting the magnet within the flywheel fan; a plate supported by but spaced from the engine frame and permitting the circulation of air therebetween, said plate supporting the magneto armature within the flywheel fan, and provided with an aperture; and a high tension conductor extending between the plate and engine frame and havin a connection with the. armature through said aperture.

6. In a magneto ignition system, the com-,

bination with an internal combustion engine having a flywheel fan located adjacent one end of the engine frame; of a magneto-generator including a aationary armature and a movable magnet; means for supporting the magnet upon the flywheel fan adjacent the .engine frame; a plate supported by but spaced from the engine frame and permitting the circulation of air therebetween, said late supporting the magneto armature adacent said magnet, and provided with an aperture; and a high tension conductor extending between the plate and engine frame and having a connection with the armature throulgh said aperture.

7. n a magneto ignition system, the combination with an internal combustion engine having a flywheel located adjacent one end of the engine frame; of a magneto-generator including a stator and a rotor; means for supporting the rotor upon the flywheel adjacent the engine frame; a plate supported by but spaced from the engine frame and supporting the stator adjacent said m at, and provided withan aperture; and a igh tension conductor extending between the plate and engine frame and having a connection with the armature through said aperture, said connection including a nonconducting lug for said aperture attached to said con uctor and provided with a recess enclosing a conductor, and including a block projecting into said recess and provided with a conductor attached to said armature and contacting with said plug conductor.

8. In a magneto ignition system,the combination with an internal combustion engine having a flywheel located adjacent one end of the engine frame; of a magneto-generator including a stator and a rotor; means for supporting the rotor upon the flywheel adjacent the engine frame; a plate supported by but spaced from the engine frame and supporting the stator adjacent said magnet, and provided with an aperture; and a high tension conductor extending between the plate and engine frame and having a connection with the armature through said aperture, said connection including a nonconducting recessed plug for said aperture attached to said conductor by means of a fastening having a head located within said recess, and including a block attached to said armature and carrying a spring electrically connected with said armature and adapted to cooperate with said fastening head; and means for detachably securing said plug upon said plate with the block extending into the plug recess.

9. In a device of the kind described, in combination, an engine having a crank case provided with a removable end wall; a flywheel cooling fan for the engine supported for rotation adjacent said removable end wall; means carried by said removable end wall and flywheel fan adapted to coo erate to form a housing within the fiywhee fan; and a generator having stator and rotor elements carried within said housing by the removable end wall and flywheel fan re spectively.

In testimony whereof I aflix my signature.

CHARLES F. KETTERING. Witnesses:

MILDRED PEARE; MARY LAYTON. 

